In general, the large carrier which is called the dump truck is provided with a vessel (a loading platform) which is made liftable on a frame of a vehicle body. This dump truck is adapted to travel in a state of loading a large amount of crushed stones on the vessel.
The traveling drive device which drives a driving wheel of the dump truck for traveling is provided with a tubular axle housing which is mounted to a vehicle body in a non-rotational state and in which a drive source is provided, a rotational shaft which is provided so as to axially extend in the axle housing and is rotationally driven by the drive source, a wheel mounting tube which is rotatably provided on the axial outside (the side axially opposite to the drive source) of the aforementioned axle housing and on its outer periphery side via a wheel support bearing and to which a wheel is mounted, a reduction mechanism which is provided between the wheel mounting tube and the aforementioned axle housing to decelerate and transmit rotation of the aforementioned rotational shaft to the wheel mounting tube, a disk holding cylinder is provided on the axial outside (the side axially opposite to the axle housing) of the wheel mounting tube, an annular brake disk which is mounted to the disk holding cylinder to rotate together with the wheel, and a brake device for applying braking to the aforementioned wheel mounting tube by pressing a friction pad against the brake disk (See, Patent Document 1).